This invention relates to feed networks for electronically scanned radars and, more particularly, to a feed network constructed of optical fibers.
Electronically scanned radars are widely used in both fixed and mobile installations. Such radars include a feed network which couples microwave energy from the transmitter to a radiating aperture of the antenna, as well as from the aperture to the receiver. Feed networks are constructed in a variety of forms, with the corporate feed being particularly useful in providing an accurate distribution of microwave energy across the radiating aperture.
A problem arises in that such feed networks, particularly the corporate feed, introduced weight and bulk to the radar antenna, a clear disadvantage in mobile applications which call for reduced weight and bulk. Furthermore, such feed networks are limited in their effectiveness by factors including electromagnetic interference, cross talk, transmission loss, and bandwidth limitations. Thus, existing feed networks place constraints on radars both in terms of their deployment and in terms of their electrical characteristics.